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241.
Klaus Mittenzwei Gudbrand Lien Wendy Fjellstad Eva Øvren Wenche Dramstad 《Journal of environmental management》2010,91(4):861-868
Protected Landscapes (PLs) are increasingly used in Norway to conserve cultural (human modified) landscapes. In many cases the maintenance of agricultural activities in PLs is required to preserve landscape character. Whilst research exists on land conservation policies in general, the particular effects of PL on management and adjustment of the farms involved have not received attention in the literature. We present results from a questionnaire sent to owners of agricultural land within PLs in Norway. Whilst landowners were divided upon the effects of PLs on farm management, the economic situation of the farm was little affected. Furthermore, changes in farm management after the establishment of a PL did not seem to have been driven by the establishment of the PLs per se. Most importantly, farm management changes were related to potential options to develop the farm and its land. A statistical model showed that PL-farms did not differ significantly from farms outside PL in the development of their land use or animal husbandry. Our findings thus indicate that the establishment of PL played a minor role as a driving force of changes in farm management and farm income. 相似文献
242.
Changes in pH and organic acids in mucilage of Eriophorum angustifolium roots after exposure to elevated concentrations of toxic elements 总被引:1,自引:0,他引:1
M. Tariq Javed Eva Stoltz Sylvia Lindberg Maria Greger 《Environmental science and pollution research international》2013,20(3):1876-1880
The presence of Eriophorum angustifolium in mine tailings of pyrite maintains a neutral pH, despite weathering, thus lowering the release of toxic elements into acid mine drainage water. We investigated if the presence of slightly elevated levels of free toxic elements triggers the plant rhizosphere to change the pH towards neutral by increasing organic acid contents. Plants were treated with a combination of As, Pb, Cu, Cd, and Zn at different concentrations in nutrient medium and in soil in a rhizobox-like system for 48–120 h. The pH and organic acids were detected in the mucilage dissolved from root surface, reflecting the rhizospheric solution. Also the pH of root–cell apoplasm was investigated. Both apoplasmic and mucilage pH increased and the concentrations of organic acids enhanced in the mucilage with slightly elevated levels of toxic elements. When organic acids concentration was high, also the pH was high. Thus, efflux of organic acids from the roots of E. angustifolium may induce rhizosphere basification. 相似文献
243.
Pinning down vulnerability: from narratives to numbers 总被引:2,自引:0,他引:2
Social vulnerability analyses have typically relied upon narratives to capture the nuances of the concept. While narratives have enhanced our understanding of the multiple drivers of vulnerability, they have had limited influence on hazards and climate adaptation policy. This is partially a function of the different needs and goals of the policy and research communities. The former prioritises generalised quantitative information, while the latter is more concerned with capturing complexity. A theoretically driven and empirically tested quantitative vulnerability and capacities index (VCI) for use at the local scale is presented to help connect vulnerability research and policy. There are four versions of the index for use in rural and urban contexts at the household and community levels. There can be an infinite number of drivers of vulnerability, but the VCI draws upon 12 indicators to represent material, institutional and attitudinal aspects of differential vulnerability and capacities. 相似文献
244.
Daniel Campo Jose Molares Lucia Garcia Pino Fernandez-Rueda Claudia Garcia-Gonzalez Eva Garcia-Vazquez 《Marine Biology》2010,157(1):147-156
The alternation of glacial and interglacial events during the Pleistocene has produced changes in species distribution ranges
leading to bottlenecks and alterations of patterns of gene flow. The European stalked barnacle, Pollicipes pollicipes, is a sessile pedunculate cirripede that inhabits the rocky intertidal frame, from Senegal to the northwestern coast of France.
In this work, we have analyzed a fragment of the mitochondrial gene cytochrome c oxidase subunit I for 569 individuals of P. pollicipes in order to investigate whether the shifts in climatic conditions that occurred during the Pleistocene influenced the current
pattern of distribution of genetic variation of P. pollicipes. A pre-last glacial maximum pattern of demographic expansion was found, in concordance with many other North Atlantic marine
species. On the other hand, three potential glacial refugia were identified: North African coasts, northwestern Iberian Peninsula
and English Channel/Brittany. 相似文献
245.
An evaluation of the social organization and sexual system of eusocial species of Synalpheus has been hindered because it has not been possible to determine the sexual composition of colony helpers (workers). The external
sexual characters typically used to sex caridean shrimps are lacking in Synalpheus. We used SEM sexing technique to determine the sexual composition of helpers in colonies of Synalpheus regalis, S. rathbunae, S. chacei, S. rathbunae A (see Morrison et al. Mol Phylogen Evol 30:563–568, 2004), and S. filidigitus. Colonies consisted of both sexes and sex ratios of helpers generally conformed to 50:50 female to male. Females were characterized
by gonopores with U-shaped slits on the coxae of the third pereopods (first walking legs) while males had oval gonopore openings
on the coxae of the fifth pereopods (third or last walking legs). In S. chacei, S. filidigitus, and S. rathbunae A, a few helpers were found that had both male and female gonopores (intersexes). All three reproductive females (queens) of
S. filidigitus examined were intersexes. Sexing of helpers allowed us to test some hypotheses about sexual differences in helper morphology
that might indicate task specialization (division of labor). Male helpers were not different from female ones in body size
(except in S. regalis: males somewhat larger) and in fighting chela size. The lack of sexual dimorphism in these characters suggests no male–female
specialization in colony tasks such as defense. The presence of male and female helpers similar in size suggests that the
sexual system of these eusocial species is gonochoristic, although protandry of some sort in S. filidigitus can not be ruled out. The intersexuality observed in a few individuals may be due to developmental anomalies, protandry,
or even simultaneous hermaphroditism. Finally, the sexing technique allowed us to establish that new colonizers of unoccupied
sponges in S. rathbunae are a single male and female of helper size. 相似文献
246.
Early onset fetal growth restriction (FGR) may be due to impaired placentation, environmental or toxic exposure, congenital infections or genetic abnormalities. Remarkable research, mainly based on retrospective series, has been published on the diverse genetic causes. Those have become more and more relevant with the improvement in the accuracy of the analysis techniques and the rising of breakthrough genomewide methods such as the whole genome sequencing. However, no publication has presented an integrated view of management of those fetuses with an early and severe affection. In this review, we explored to which extent genetic syndromes can cause FGR fetuses without structural defects. The most common chromosomal abnormalities (Triploidies and Trisomy 18), submicroscopic chromosomal anomalies (22q11.2 microduplication syndrome) and single gene disorders (often associated with mild ultrasound findings) related to early and severe FGR had been analysed. Finally, we addressed the impact of epigenetic marks on fetal growth, a matter of growing importance. At the end of this review, we should be able to provide an adequate counseling to parents in terms of diagnosis, prognosis and management of those pregnancies. 相似文献
247.
248.
Klaus Scheuch Eva Haufe Attiya Khan 《International journal of occupational safety and ergonomics》2013,19(4):527-541
This article deals with the special demands on occupational medicine due to the changes of work and of tasks at workplaces. Conclusions for research in occupational medicine are drawn from these processes. They are discussed on the basis on an analysis of literature from the years 1980–1998. Focus of future research in the field of occupational medicine is developed by taking international tendencies, the interdisciplinary setting of occupational medicine, and the close relations between science and practice into consideration. 相似文献
249.
Hanslík E Jedináková-Krízová V Ivanovová D Kalinová E Sedlárová B Simonek P 《Journal of environmental radioactivity》2005,81(2-3):307-320
A near field study was set up to follow the effects of the Temelin nuclear power plant construction. Reference levels of artificial radionuclides were monitored in the Vltava River upper course and its tributaries in the period 1990-2001. Monitoring continued even after the waste water release startup during the pilot operation in 2002. The assessment of the (90)Sr and (137)Cs concentrations histories in ground water, river bottom sediments and fish showed a decreasing trend. This trend was not influenced by the nuclear power plant pilot operation. In the case of tritium, trend of increasing concentration had been already observed since the pilot operation startup. The monitoring of changes in concentrations of artificial and natural radionuclides in influenced and uninfluenced profiles will be maintained to assess the possible influence of the operation of the Temelin nuclear power plant. 相似文献
250.